Field
The disclosure is related to the field of environmental testing; for example, the testing of food, materials, surfaces, and/or equipment, for instance surfaces or equipment with which food comes into contact during preparation or processing.
Description of the Related Art
Safety in the food industry is of growing concern. In recent years, approaches to monitoring and controlling contamination and hygiene, have increasing employed HACCP (Hazard Analysis and Critical Control Point) principles. Such approaches are not only directed at controlling the occurrence of pathogenic microorganisms, but are also directed at preventing hazards before these hazards become widespread and expensive problems. HACCP is the science-based system accepted internationally for ensuring food safety. HACCP has been adopted by the FDA and USDA as well as by other countries. HACCP has been endorsed by the National Academy of Sciences, the Codex Alimentarius Commission (an international food standard-setting organization), and the National Advisory Committee on Microbiological Criteria for Foods. Developed over 40 years ago for the space program, HACCP has proven to be effective to ensure that food safety hazards are controlled to prevent unsafe food from reaching the consumer.
In the United States alone, since 1995, HACCP-based systems have been mandated for the following industries by the Federal Government:                Seafood—(21 C.F.R. Parts 123 and 1240 Procedures for the Safe and Sanitary Processing and Importing of Fish and Fishery Products; Final Rule) in December, 1995        Meat and Poultry—(9 C.F.R. Part 304, et al, Pathogen Reduction: Hazard Analysis and Critical Control Point (HACCP) Systems; Final Rule) in July, 1996        Fruit and Vegetable Juice—(21 C.F.R. Part 120: Hazard Analysis and Critical Control Point (HACCP); Procedures for the Safe and Sanitary Processing and Importing of Juice; Final Rule) in January, 2001.        
Reliance on HACCP will continue for the foreseeable future.
In order for a food manufacturer or handler to effectively comply with HACCP-based requirements or standards, it is vital that the food manufacturer or handler have an effective system in place to collect, monitor, and analyze relevant HACCP data. The necessity for this can be seen by examining the seven HACCP principles required for compliance:                1. Conduct a hazard analysis.        2. Determine the critical control points (CCP). A CCP is a point, step or procedure in a food process where a number of possible measurement controls can be applied and, as a result, a food safety hazard can be prevented, eliminated, or reduced to acceptable levels.        3. Establish measurement parameters and critical limits for each CCP and identify methods for measuring the CCP. For example, compliance with a cooking CCP may be assessed by the combination of two indicators: time and temperature.        4. Monitor the CCP to ensure ongoing compliance with established critical limits. A monitoring system should not only detect individual deviations, but also analyze data to identify patterns of deviation that could indicate a need to reassess the HACCP plan.        5. Establish corrective actions to be taken when monitoring of important parameters shows that a critical limit has not been met.        6. Maintain accurate records. Effective record keeping is a requirement. HACCP records must be created at the time events occur and include the parameter measurement, date, time and the plant employee making the entry.        7. Verify that the system is working properly initially as well as ongoing. These activities include calibration of the monitoring equipment, direct observations of the monitoring activities and a review of the records.        
One essential characteristic of the HACCP system that differentiates it from previous inspection system(s) is that it places responsibility for food safety directly on the food manufacturer or handler. Each food processor or handler must be able to identify CCPs, measure a variety of parametric indicators for each CCP (e.g., time and temperature measurements to verify a cooking process), identify deviations, perform trend analysis of deviations, and document the data to show compliance with the HACCP requirements.
It is not surprising that the growing reach of HACCP-based systems is progressing concurrently with a trend toward methods of testing that are improved by being more rapid, more sensitive and easier to perform. More stringent standards, such as those associated with HACCP-based systems, are expected to motivate such improvements in methods of testing. The reverse is also true in that as test methods improve, standards are likely to become more stringent, since compliance can be more accurately, precisely, and efficiently maintained and verified.
This trend toward improved testing is occurring in a wide variety of industries, including, but not limited to, those industries related to food, pharmaceuticals, cosmetics, and medical areas. In such industries, many techniques are used to monitor levels of environmental quality, including techniques that use microbiological cultures. Microbiological cultures are a most widely conducted test method, but due to their low-test throughput capacity and long incubation time periods, are of limited use. They cannot measure the quality of the environment immediately prior to commencement of an operation. A variety of tests have been developed which detect and in some cases quantify specific pathogens. They can range from high-throughput automated systems to single-sample test devices. These methods require the growth of microorganisms for detection, which consumes considerable time. Monitoring levels of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and alkaline phosphatase (AP), make use of parameters that indirectly correlate to the level or degree of environmental contamination. Still others monitor factors related to risk of the presence and propagation of microorganisms, i.e., temperature, pH, conductivity and protein residues. The latter types of methods are usually real-time in their determinations, offering a distinct advantage for the user in obtaining critical environmental quality information on an immediate basis.
Typically, bioluminescent techniques are used to detect the presence of ATP and AP and similar targets. The protocol involves using a device (e.g. swab) to collect a sample from a surface of interest, and activation of the device to mix reagents together with the sample to produce light proportional to the amount of ATP/AP sampled. The reaction is then read by inserting the device into a photon measuring instrument.
One bioluminescent ATP monitoring system is the LIGHTNING system developed by IDEXX LABORATORIES. The device contains a pre-moistened swab, buffer in a bulb at one end and lyophilized reagent in a foil sealed compartment at the reading end. The swab is removed from the device, used to collect a sample from a test surface, and returned to the tube of the device. The bulb is then bent to break open a snap valve, which releases the buffer into the reading chamber when the bulb is squeezed. The sample-containing swab is then pushed through a foil barrier, the device is shaken and the reaction proceeds between ATP on the swab and the dissolved (in the buffer) reagent. The device is inserted into the reading chamber of the photon measuring instrument and a reading is taken over a ten-second integration period. The intensity of the bioluminescent signal is proportional to ATP on the swab.
Another system is called the CHARM SCIENCES POCKETSWAB PLUS. It is an integrated device used with a LUMINATOR T portable luminometer. The device contains a pre-moistened swab. It is removed from the device base, used to swab a surface, returned to the base, then activated by screwing the top portion relative to the base. This action causes the swab tip to puncture separation barriers allowing separate reagents to migrate to the bottom chamber of the base, mixing and reacting with the sample collected on the swab. Shaking is required to facilitate reagent transfer to the bottom and mixing in the bottom chamber. The activated device is then inserted into a hole in the top of the luminometer and pushed down until it meets a stop. This process displaces a door. The upper portion of the device remains exterior to the instrument, but forms a seal with the reading chamber orifice. A read button in the instrument is then pressed to initiate a signal integration period before a reading is displayed in relative light units (RLU).
Another such system is the BIOTRACE CLEAN-TRACE RAPID CLEANLINESS TEST self-contained device for use with the UNI-LITE XCEL portable luminometer. It also has a pre-moistened swab, which is removed, a sample is collected, and the swab returned. Activation involves forcing the top portion of the device, which contains the sample, down into the base, through membrane barriers. The swab engages a piercing tip, which breaks the membranes and allows the reagents to mix in a manner similar to that of the CHARM device. Shaking is required to transfer all of the solution to the bottom. The BIOTRACE luminometer has a cap, which lifts and swivels out of the way to expose the reading chamber. The sample-containing device is lowered into the chamber and the cap is closed. Full closure of the cap opens a light blocking member to allow signal measurement. Like the CHARM unit, a button begins the read cycle, which ends with the light reading display in RLUs.
MERCK also offers a Another hygiene monitoring system for ATP that is the HY-LITE Monitor by MERCK which employs HY-LITE test swabs, rinse tubes and sampling pens. The swab is moistened in the rinse tube. A surface is swabbed. The swab is returned to the tube and rotated for several seconds to release any collected ATP. The swab is squeezed out and removed. Then the pen is inserted for one second to pick up the sample. The tip of the pen is struck on a hard pad to engage the cuvette. A button is pushed to release the reagents and initiate the reaction in the cuvette. The cuvette is then removed and shaken, it is inserted into the monitor's reading chamber, and a button is pressed to initiate a ten-second light integration period. RLUs are then displayed on the monitor screen.
A similar system has been developed by CELSIS called the SYSTEMSURE portable hygiene monitoring system. The test sequence is similar to that of the MERCK system where the swab is moistened and the surface is swabbed. The reagent is then pipetted into the cuvette. The swab is inserted into the cuvette and rotated for several seconds, then removed. The cuvette is capped and inserted into the luminometer, where the reading is initiated.
There is a need for an improved method and apparatus that is designed to enhance ease of use and to improve measurement accuracy and precision. Many of the current systems incorporate unnecessary actions by the operators that are burdensome with respect to certain steps such as pre-moistening, pipetting, rotating, two-handed screwing, two-handed pushing, striking, shaking, and precise timing, which do not adequately control device activation and contribute to increased reading variances. Many of the current systems are slow in operation and may not be able to produce highly accurate results. Such systems may also consume a relatively large amount of electrical power, thus may not be suitable for convenient mobile use.
The present application describes various methods and apparatus which may address limitations of existing systems.